TWI572726B - Surface treatment copper foil and its manufacturing method, printed wiring board with copper laminated board and printed wiring board - Google Patents

Description

Surface-treated copper foil and its manufacturing method, copper-clad laminate for printed wiring board, and printed wiring board

The present invention relates to a surface-treated copper foil, a method for producing the same, a copper-clad laminate for a printed wiring board, and a printed wiring board.

In recent years, miniaturization and high functionality of electronic devices such as mobile electronic devices have been required, and printed wiring boards have been required to be finer (reduce) in wiring patterns. In order to cope with such a request, the copper foil for manufacturing a printed wiring board is preferably thinner than the conventional one and has a low surface roughness.

In addition, although the copper foil for manufacturing a printed wiring board is bonded to an insulating resin substrate, how to ensure the adhesion strength between the copper foil and the resin insulating substrate is important. This is because when the adhesion strength is low, wiring peeling easily occurs in the production of a printed wiring board, resulting in a decrease in product yield. In this case, in the copper foil for manufacturing a printed wiring board, the bonding surface of the copper foil is roughened to form irregularities, and the unevenness is infiltrated into the insulating resin substrate by press working, thereby exerting a anchoring effect. Thereby improving the adhesion. However, the method of using the roughening treatment is incompatible with the copper foil which is thinner than the conventional one and has a low surface roughness in accordance with the above-described macroscopication.

There is also known a copper foil for a printed wiring board which does not impart a roughening treatment and which improves the adhesion between the copper foil and the insulating resin substrate. For example, the surface of the surface treatment layer is provided on the bonding surface of the copper foil used in the production of the copper-clad laminate when the copper-clad laminate is bonded to the insulating resin substrate, as disclosed in Japanese Laid-Open Patent Publication No. 2010-18855. The copper foil is provided on the bonding surface of the copper foil to which the cleaning treatment is applied, and the surface treatment layer formed by attaching a high melting point metal component and a carbon component having a melting point of 1400 ° C or higher by a dry film formation method is provided. Surface treated copper foil.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-18855

The present inventors have obtained the following findings: by forming a lanthanum-based surface treatment layer in which hydrogen and/or carbon are added at a specific concentration on at least one side of the copper foil, it is possible to provide vapor deposition even by sputtering or the like. The surface of the extremely flat copper foil formed by the method can also achieve a high adhesion strength to the resin layer, and a copper foil having a surface treatment layer of an ideal insulation resistance suitable for the micronization of the printed wiring board.

Therefore, an object of the present invention is to provide a highly flat copper foil surface which is formed by a vapor deposition method such as sputtering, and which can achieve high adhesion strength to a resin layer and have a microchip suitable for a printed wiring substrate. The copper foil of the surface treated layer of the ideal insulation resistance of the pitch.

According to one aspect of the present invention, there is provided a surface-treated copper foil comprising a copper foil and being disposed on at least one side of the copper foil, having a hydrogen concentration of 1 to 35 atomic % and/or a carbon concentration of 1 to 15 atoms % is a surface treatment layer composed of tantalum.

According to still another aspect of the present invention, there is provided a copper-clad laminate for a printed wiring board comprising the surface-treated copper foil according to the above aspect and a resin layer provided in close contact with the surface-treated layer.

According to another aspect of the present invention, there is provided a printed wiring board comprising a layer of a resin layer sequentially formed of ruthenium having a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%. The layer is composed of a layer of a copper layer.

According to another aspect of the present invention, there is provided a method of producing a surface-treated copper foil according to the above aspect, comprising: preparing a copper foil; and forming a film by a physical vapor phase or a chemical vapor phase The film is formed on at least one side of the copper foil to form a surface treatment layer composed of ruthenium having a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%.

10‧‧‧ Copper foil with carrier

12‧‧‧ Carrier

14‧‧‧heat resistant metal layer

16‧‧‧ peeling layer

18‧‧‧very thin copper foil layer

20‧‧‧Surface treatment layer

21‧‧‧Resin solution

22‧‧‧ Primer resin layer

24‧‧‧With copper foil with carrier

25‧‧‧Bronded laminate with carrier

26‧‧‧Resin substrate

28‧‧‧ Copper-clad laminate

30‧‧‧Electroplating copper

32‧‧‧Sampling for peel strength measurement

34‧‧‧Light resistance

36‧‧‧Electroplating copper

38‧‧‧Micro wiring pattern

Fig. 1 is a flow chart showing the manufacturing process of a copper foil having a carrier in Examples 1 to 15.

Fig. 2 is a flow chart showing the manufacturing process of the copper-clad laminate in Examples 1 to 15.

Fig. 3 is a flow chart showing the manufacturing process of the sample for peel strength measurement in Examples 1 to 15.

4 is a flow chart showing the formation of a fine wiring pattern in Examples 1 to 15.

Fig. 5 is a SEM photograph of the fine wiring pattern observed in Example 5.

Fig. 6A is a view showing an interface between the ultra-thin copper foil layer 18, the surface treatment layer 20, and the primer resin layer 22 in the copper-clad laminate obtained in Example 5 by STEM-EDS.

Fig. 6B is a Si element map image of the interface portion indicated by the enlarged portrait in Fig. 6A.

Fig. 6C is a Cu element map image of the interface portion indicated by the enlarged portrait in Fig. 6A.

Surface treated copper foil

The surface-treated copper foil of the present invention comprises a copper foil and a surface treatment layer provided on at least one side of the copper foil. Even if desired, the surface treatment layer may be provided on both sides of the copper foil. Further, the surface treatment layer is a layer composed of ruthenium having a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%. In this way, by forming a lanthanum-based surface treatment layer to which hydrogen and/or carbon is added at a specific concentration, it is possible to provide a surface of a copper foil having an extremely flat surface formed by a vapor deposition method such as sputtering. High-density connection of resin layer A copper foil having a surface treatment layer of an ideal insulation resistance suitable for printing a printed wiring board.

In particular, in order to form a wiring pattern having a height-reduced line/gap (L/S) of, for example, 13 μm or less/13 μm or less (for example, 12 μm/12 μm, 10 μm/10 μm, 5 μm/5 μm, 2 μm/2 μm), it is desirable to Use an ultra-thin copper foil that has never been seen before (for example, a thickness of 1 μm or less). However, when such an extremely thin copper foil is to be produced by electrolytic foil-forming, the problem of pinhole formation or the like is likely to occur due to too thin. Further, although it is proposed to produce an ultra-thin copper foil having a thickness of 3 μm or less by sputtering without using a conventional electrolytic foil-forming method, the extremely thin copper foil thus formed has extremely flat copper. Since the surface of the foil (for example, the arithmetic mean roughness Ra: 200 nm or less) is not expected to be used for the anchoring effect of the unevenness on the surface of the copper foil, it is extremely difficult to ensure high adhesion strength between the ultra-thin copper foil and the resin layer. In this regard, the surface-treated copper foil of the present invention is not the same as the conventional ultra-thin copper foil, and the physical properties such as the anchoring effect are used to ensure the adhesion, and the chemical property of the composition of the surface treatment layer can be controlled. The method achieves adhesion to the resin layer. That is, a surface treatment layer made of tantalum, which has a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%, is formed on at least one side of the copper foil, even by sputtering or the like. The extremely flat copper foil surface formed by the vapor deposition method can also achieve high adhesion strength to the resin layer. Further, the surface treatment layer having the above-described composition can also realize an ideal insulation resistance which can be suitable for the miniaturization of the printed wiring board, thereby preventing leakage current from being generated between the wirings in the macro wiring pattern.

Therefore, the surface-treated copper foil of the present invention is preferably produced by using a copper-clad laminate for a printed wiring board, and in this production, a resin layer (typically an insulating resin layer) is laminated on the surface.

The copper foil constituting the surface-treated copper foil of the present invention may be produced by any method. Therefore, even if the copper foil is an electrolytic copper foil or a rolled copper foil, when the copper foil is prepared in the form of a copper foil having a carrier, it is wet-formed by an electroless copper plating method or an electrolytic copper plating method. A physical vapor deposition method such as a film method, sputtering, or vacuum evaporation, a chemical vapor deposition film, or a copper foil formed by the combination may be used. From the viewpoint of easily meeting the miniaturization by extremely thinning (for example, a thickness of 3 μm or less), a particularly preferable copper foil is produced by physical vapor deposition such as sputtering or vacuum evaporation. The copper foil is most preferably a copper foil produced by a sputtering method. Further, although the copper foil is preferably a copper foil which is not roughened, it is not subject to preliminary roughening or soft etching treatment, washing treatment, or oxidation as long as it does not hinder the formation of the wiring pattern when the printed wiring board is manufactured. The reduction treatment may also result in secondary coarsening. The thickness of the copper foil is not particularly limited, and is preferably 50 to 3000 nm, more preferably 75 to 2,000 nm, still more preferably 90 to 1,500 nm, and particularly preferably 100 to 1000 nm, in order to correspond to the above-described macroization. 100~700nm. It is preferable that the copper foil having such a thickness in the range of sputtering is produced by the sputtering method in terms of in-plane uniformity of film thickness or productivity of flakes or rolls.

The surface of the surface-treated layer side of the copper foil constituting the surface-treated copper foil of the present invention preferably has an arithmetic mean roughness Ra of 200 nm or less measured according to JIS B 0601-2001, preferably 1 to 180 nm, more preferably 2~175nm, especially 3~130nm, best 5~100nm . In this way, the smaller the arithmetic mean roughness, the higher the thickness of the printed wiring board produced by using the surface-treated copper foil can be formed into a line/gap (L/S) of 13 μm or less / 13 μm or less (for example, 12 μm/ A wiring pattern of the same degree as 12 μm to 2 μm / 2 μm. Further, the surface of the copper foil having such an extremely flat surface cannot be expected to utilize the anchoring effect of the unevenness on the surface of the copper foil. However, the surface-treated copper foil of the present invention is not secured by the physical method like the anchoring effect described above. The adhesion can be improved by the chemical method of controlling the composition of the surface treatment layer.

As described above, the surface-treated copper foil of the present invention may be provided in a form of a copper foil having a carrier. In the case of an extremely thin copper foil, the operability can be improved by making it a copper foil having a carrier. In particular, when a copper foil is produced by vacuum vapor deposition such as sputtering, it can be preferably produced by using a copper foil having a carrier. As shown in FIG. 1(a), the copper foil 10 having a carrier is provided with a release layer 16, an ultra-thin copper foil layer 18, and a surface treatment layer 20 on the carrier 12, even in the carrier 12 and the release layer 16. The heat resistant metal layer 14 may be provided between them. Further, the above-described various layers may be provided in this order on the both sides of the carrier 12 so as to be vertically symmetrical. The copper foil having a carrier is not particularly limited as long as it has the above-described ultra-thin copper foil layer 18 and surface treatment layer 20, and a known layer configuration is employed. Examples of the carrier include a metal foil such as a copper foil, a nickel foil, a stainless steel foil, or an aluminum foil, and a PET film, a PEN film, an aromatic polyamide film, a polyimide film, a nylon film, and a liquid crystal. a resin film such as a polymer, or a metal coated tree having a metal layer coating on the resin film For the lipid film, etc., copper foil is preferred. The copper foil as a carrier may be either a rolled copper foil or an electrolytic copper foil. The thickness of the carrier is typically 210 μm or less, and is preferably from 10 to 210 μm from the viewpoint of transportability of the copper foil having a carrier and prevention of breakage at the time of peeling of the carrier. Preferable examples of the metal constituting the heat resistant metal layer 14 include iron, nickel, titanium, tantalum, and tungsten, and titanium is particularly preferable. These metals have high stability as interdiffusion barriers at the time of high-temperature press working, etc. Titanium exhibits excellent high-temperature heat resistance because its passivation film is composed of a very strong oxide. At this time, it is preferable that the titanium layer is formed by a physical vapor phase film formed by a sputtering method. The heat resistant metal layer 14 such as a titanium layer is preferably a converted thickness of 1 to 50 nm, more preferably 4 to 50 nm. It is preferable to provide at least one of the carbon layer and the metal oxide layer on the heat resistant metal layer 14 (particularly the titanium layer) as the peeling layer 16, more preferably a carbon layer. The interdiffusion property and reactivity of carbon and a carrier are small, and even if it is subjected to press working at a temperature exceeding 300 ° C, metal coupling can be prevented from being formed by high-temperature heating between the copper foil layer and the joint interface, and the carrier can be easily peeled off. The state of removal. The carbon layer is also preferably formed by forming a film using a physical vapor phase such as sputtering. The converted thickness of the carbon layer is preferably 1 to 20 nm. In addition, the "converted thickness" refers to a chemically quantitative analysis of the amount of component adhesion per unit area, and the thickness calculated from the amount of analysis.

The surface treatment layer constituting the surface-treated copper foil of the present invention is a lanthanoid surface treatment layer composed of ruthenium having a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%. The ruthenium constituting the lanthanide surface treatment layer is typically amorphous ruthenium. It is considered that the resin layer and the adhesion and the insulation resistance can be achieved by causing the lanthanide surface treatment layer to contain at least one of hydrogen and carbon. However, the lanthanide surface treatment layer preferably has a hydrogen concentration of 1 to 35 atom% and a carbon concentration of 1 to 15 atom%. In addition, the lanthanoid material constituting the surface treatment layer may contain unavoidable impurities which are inevitably mixed due to a raw material component or a film formation process. For example, when a conductive dopant such as boron for DC sputtering is added to a sputtering target, although such a dopant is inevitably slightly mixed into the surface treatment layer, it is not so Avoid mixing of impurities is allowed. Further, the lanthanide surface treatment layer may contain other dopants as long as it does not deviate from the gist of the invention. Further, since the ruthenium is exposed to the atmosphere after film formation, the presence of oxygen which is mixed therein is allowed.

Further, the niobium atom content in the lanthanoid surface treatment layer is preferably from 50 to 98% by atom, more preferably from 55 to 95% by atom, still more preferably from 65 to 90% by atom. When it is in such a range, the insulating properties and heat resistance of the amorphous crucible are significantly exhibited. Further, the content of the lanthanum element is measured by a high-frequency glow discharge luminescence surface analysis device (GDS).

The hydrogen concentration of the lanthanide surface treatment layer is preferably from 1 to 35 atom%, preferably from 10 to 31 atom%, more preferably from 15 to 30 atom%, particularly preferably from 20 to 30 atom%, most preferably 22~ 26 atomic %. The carbon concentration of the lanthanide surface treatment layer is preferably 1 to 15 atom%, preferably 3 to 13 atom%, more preferably 4 to 12 atom%, particularly preferably 5 to 12 atom%, most preferably 6~ 11 atom%. The carbon concentration and/or the hydrogen concentration are preferably such that when the carbon concentration and the hydrogen concentration are within the above range, the adhesion to the resin layer and the insulation resistance are remarkably improved.

The measurement of the hydrogen concentration and carbon concentration of the lanthanide surface treatment layer can be It is carried out by measuring the depth distribution by Raseford back scattering spectrometry (RBS), hydrogen forward scattering analysis (HFS) or nuclear reaction analysis (NRA). Examples of the apparatus used for such measurement include Pelletron 3SDH (manufactured by National Electrostatics Corporation). This concentration measurement can be carried out from the lanthanide surface treatment layer after film formation on the copper foil. In addition, in the form of a printed wiring board or an electronic component manufactured by using the surface-treated copper foil of the present invention to be described later, polishing is performed from the surface until the wiring pattern is exposed from the surface-treated copper foil, and thereafter, the wiring is etched. The pattern exposes the surface treatment layer, whereby the above-described concentration measurement can be performed.

The surface treatment layer preferably has a thickness of 0.1 to 100 nm, preferably 2 to 100 nm, more preferably 2 to 20 nm, and particularly preferably 4 to 10 nm. When it is within such a range, the adhesion to the resin layer and the insulation resistance can be remarkably improved.

Production method

According to the surface-treated copper foil of the present invention, by preparing the copper foil and forming a film by physical vapor deposition or chemical vapor deposition, a hydrogen concentration of 1 to 35 atom% is formed on at least one side of the copper foil. / or a surface treatment layer composed of ruthenium having a carbon concentration of 1 to 15% by atom. As described above, a surface treatment layer may be formed on both sides of the copper foil as desired.

Even if the copper foil used in the production method of the present invention is produced by any method, it is as described above in detail. Therefore, from the viewpoint of easily meeting the miniaturization (for example, the thickness of 1 μm or less). It is to be noted that a particularly preferable copper foil is a copper foil produced by physical vapor deposition of a sputtering method or the like, and is preferably a copper foil produced by a sputtering method, and such a copper foil has a carrier. The shape of the copper foil is better prepared.

In the production method of the present invention, the formation of the surface treatment layer is formed by physical vapor deposition or chemical vapor deposition. By using a physical vapor phase film formation or a chemical vapor phase film formation, it is easy to control the content of hydrogen and/or carbon, and it is possible to form an extremely thin thickness (0.1 to 100 nm) which is expected to be formed into a surface treatment layer. Therefore, it is possible to preferably produce a lanthanide surface treatment layer having a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%.

The surface treatment layer is preferably formed by film formation by physical vapor phase. Examples of the physical vapor phase film formation include a sputtering method, a vacuum deposition method, and an ion implantation method, and the sputtering method is preferred. According to the sputtering method, the flatness of the surface of the copper foil is not damaged (preferably, the arithmetic mean roughness Ra: 200 nm or less), and the extremely thin surface treatment layer can be formed extremely well. Further, when the copper foil 10 having the carrier shown in Fig. 1(a) is used, the heat resistant metal layer 14 which is provided on the carrier 12 by the sputtering method, the peeling layer 16, and the extremely thin layer are also used. The point at which all the layers of the copper foil layer 18 and the surface treatment layer 20 are particularly high in manufacturing efficiency.

The physical vapor phase film formation system preferably uses a ruthenium target and/or a ruthenium carbide target, and is preferably carried out simultaneously with at least one additive component containing a carbon source and a hydrogen source in a non-oxidizing atmosphere. In this case, it is preferred that the component to be added is at least one selected from the group consisting of methane, ethane, propane, butane, acetylene and tetraethoxydecane. It is preferable that either of these raw materials functions as both a carbon source and a hydrogen source in one component.

The physical vapor phase film formation is not particularly limited as long as it is carried out according to well-known conditions using a well-known physical vapor deposition film forming apparatus. For example, when the sputtering method is employed, the sputtering method may be variously known by magnetron sputtering, two-pole sputtering, etc., but the film formation speed by magnetron sputtering is high and the productivity is high. The point is better. In addition, sputtering can be performed by any of DC (direct current) and RF (high frequency), and when DC sputtering is performed, conductivity is imparted to the target, so that the film forming efficiency is improved. From the viewpoint of the above, it is preferred to add a trace amount (for example, 0.01 to 500 ppm) of a conductive dopant. Examples of the conductive dopant include boron, aluminum, antimony, phosphorus, and the like. However, from the viewpoints of the film formation rate efficiency, toxicity avoidance, and moisture resistance of sputtering film formation, Boron is the best. Further, it is preferable that the degree of vacuum reaching the chamber before the start of the splash is less than 1 × 10 ^-4 Pa. As the gas used for the sputtering, an inert gas such as argon gas or the like which is a raw material of the additive component (preferably methane, ethane, propane, butane, acetylene, tetraethoxydecane or the like) Any combination) is preferred to use together. The most preferred gas is a combination of argon and methane gas. The flow rate of the argon gas is appropriately determined depending on the size of the sputtering chamber and the film formation conditions, and is not particularly limited. In addition, it is preferable that the pressure at the time of film formation is in the range of 0.1 to 2.0 Pa from the viewpoint of the operation failure such as abnormal discharge or poor plasma irradiation, and maintaining the continuous film forming property. The pressure range may be set by adjusting the flow rate of the film forming power and the argon gas according to the device structure, the capacitance, the exhaust capacity of the vacuum pump, the rated capacity of the film forming power source, and the like. In addition, the sputtering power may be appropriately set in the range of 0.05 to 10.0 W/cm ² per unit area in consideration of film thickness uniformity and productivity of the film formation.

Copper-clad laminate for printed wiring board

According to a preferred aspect of the present invention, there is provided a copper-clad laminate for a printed wiring board comprising the surface-treated copper foil of the present invention and a resin layer provided in close contact with the surface-treated layer. The surface-treated copper foil may be provided on one side of the resin layer, even if it is provided on both sides.

The resin layer contains a resin, preferably an insulating resin. The resin layer is preferably a prepreg and/or a resin sheet. The prepreg is a general term for a composite material in which a synthetic resin is immersed in a substrate of a synthetic resin sheet, a glass plate, a glass woven fabric, a glass nonwoven fabric, or paper. Preferable examples of the insulating resin include an epoxy resin, a cyanate resin, a bismaleimide triazine resin (BT resin), a polyphenylene ether resin, and a phenol resin. In addition, examples of the insulating resin constituting the resin sheet include an insulating resin such as an epoxy resin, a polyimide resin, a polyester resin, or a polyphenylene ether resin. In addition, the resin layer may contain various inorganic filler particles such as ceria, talc, and alumina, from the viewpoint of improving the insulating properties and the like. The thickness of the resin layer is not particularly limited, and is preferably 1 to 1000 μm, more preferably 2 to 400 μm, still more preferably 3 to 200 μm. The resin layer may be formed of a plurality of layers. For example, even if one outer layer of the prepreg (two sheets on both sides) is provided on each of the two sides of the inner layer prepreg, the resin layer may be formed. The dip may be composed of two or more layers. From the viewpoint of the stability of the bonding strength of the copper foil, the scratch prevention of the surface of the copper foil, etc., the resin layer such as a prepreg and/or a resin sheet is a primer resin previously coated on the surface of the copper foil. The layer is preferably provided on the surface treated copper foil.

Printed wiring board

The surface-treated copper foil of the present invention is preferably used for producing a printed wiring board. That is, according to the present invention, a printed wiring board having a layer structure derived from a surface-treated copper foil is also provided. At this time, the printed wiring board includes a layer of a resin layer which is sequentially laminated, and a layer composed of tantalum and a layer of a copper layer mainly composed of a hydrogen concentration of 1 to 35 atom% and/or a carbon concentration of 1 to 15 atom%. The layer mainly composed of ruthenium is a layer derived from the lanthanide surface treatment layer of the surface-treated copper foil of the present invention, and the copper layer is a layer derived from the copper foil of the surface-treated copper foil of the present invention. Further, the resin layer is as described above in connection with the copper-clad laminate. In either case, the printed wiring board may be formed of a known layer in addition to the surface-treated copper foil of the present invention. Specific examples of the printed wiring board include a laminate (CCL) in which the surface-treated copper foil of the present invention is bonded to one side or both sides of a prepreg, and one or both sides of the circuit are formed. A printed wiring board, or a multilayer printed wiring board or the like. Further, as another specific example, a flexible printed wiring board in which a surface-treated copper foil of the present invention is formed on a resin film to form a circuit, a COF, a TAB tape, or the like can be given. Further, as another specific example, a copper foil (RCC) having a resin coated with the resin layer is formed on the surface-treated copper foil of the present invention, and after the resin layer is laminated on the printed substrate as an insulating bonding material, The surface-treated copper foil is used as a wiring layer to form an additional wiring board of a circuit by a modified semi-additive (MSAP) method, a subtractive method, or the like, and alternately repeats a resin laminated on the semiconductor integrated circuit. Copper foil and circuit formed directly on the wafer. To be more specific For example, an antenna element in which the above-described copper foil having a resin is laminated on a substrate, and an electronic component or window for a panel display in which a layer is laminated on a glass or a resin film and formed with a pattern is also used. An electronic material for glass, an electromagnetic wave shielding film coated with a conductive adhesive on the surface-treated copper foil of the present invention, or the like.

[Examples]

The invention will be more specifically illustrated by the following examples.

Example 1~15

(1) Making a copper foil with a carrier

As shown in FIG. 1, a heat-resistant metal layer 14, a peeling layer 16, an ultra-thin copper foil layer 18, and a surface treatment layer 20 are sequentially formed on an electrolytic copper foil as a carrier 12 to form a copper foil 10 having a carrier. Further, a primer resin layer 22 is formed on the copper foil 10 having a carrier to obtain a copper foil 24 having a carrier. At this time, the film formation of the surface treatment layer 20 was carried out in accordance with various conditions shown in Tables 1 and 2. The specific procedure is as follows.

(1a) Preparation of the carrier

An electrolytic copper foil (manufactured by Mitsui Mining & Mining Co., Ltd.) having a gloss surface of 18 μm in thickness and an arithmetic mean roughness of 60 to 70 nm was prepared as the carrier 12. The carrier is subjected to a pickling treatment. The pickling treatment removes the surface oxide film by immersing the carrier in a dilute sulfuric acid solution having a sulfuric acid concentration of 150 g/l and a liquid temperature of 30 ° C for 30 seconds, and then drying it after washing with water. get on.

(1b) Formation of a heat resistant metal layer

On the glossy side of the carrier 12 (electrolytic copper foil) after the pickling treatment, a titanium layer having a thickness of 10 nm was formed by sputtering to obtain the heat resistant metal layer 14 by the following apparatus and conditions.

Device: Winding type DC sputtering device (manufactured by Japan Vacuum Technology Co., Ltd., SPW-155)

Target: Titanium target of 300 mm × 1700 mm size.

Reaching degree of vacuum Pu: less than 1 × 10 ^-4 Pa

Sputtering pressure PAr: 0.1Pa

Sputtering power: 30kW

(1c) Formation of peeling layer

A carbon layer having a thickness of 2 nm was formed on the heat-resistant metal layer 14 (titanium layer) by sputtering under the following apparatus and conditions as the peeling layer 16.

Device: Winding type DC sputtering device (manufactured by Japan Vacuum Technology Co., Ltd., SPW-155)

Target: Carbon target of 300 mm × 1700 mm size.

Reaching degree of vacuum Pu: less than 1 × 10 ^-4 Pa

Sputtering pressure PAr: 0.4Pa

Sputtering power: 20kW

(1d) Formation of extremely thin copper foil layer

On the release layer 16 (carbon layer), an ultra-thin copper foil layer 18 having a film thickness of 250 nm was formed by sputtering under the following apparatus and conditions. The ultra-thin copper foil layer obtained had a surface having an arithmetic mean roughness (Ra) of 46 nm.

Device: Winding type DC sputtering device (manufactured by Japan Vacuum Technology Co., Ltd., SPW-155)

Target: copper target with a diameter of 8吋 (203.2mm)

Reaching degree of vacuum Pu: less than 1 × 10 ^-4 Pa

Gas: argon (flow: 100sccm)

Sputtering pressure: 0.45Pa

Sputtering power: 1.0kW (3.1W/cm ² )

(1e) Formation of surface treatment layer

On the ultra-thin copper foil layer 18, a tantalum layer was formed by sputtering as the surface treatment layer 20 under the following apparatus and conditions, thereby producing a copper foil having a carrier.

Device: Winding type DC sputtering device (manufactured by Japan Vacuum Technology Co., Ltd., SPW-155)

Target: bismuth target doped with 200 ppm boron of 8 吋 (203.2 mm)

Reaching degree of vacuum Pu: less than 1 × 10 ^-4 Pa

Gas: argon (flow: 100sccm) methane gas (flow: 0~3.0sccm)

Sputtering pressure: 0.45Pa

Sputtering power: 250W (0.8W/cm ² )

At this time, in Examples 1 to 8, as shown in Table 1, the surface was The film thickness of the treatment layer was set to be constant (6 nm), and the flow rate of the methane gas of the gas was controlled to change the hydrogen concentration and the carbon concentration in the ruthenium layer. Further, in Examples 9 to 15, as shown in Table 2, the flow rate of the methane gas was constant (1.5 sccm), and the film thickness of the tantalum layer was changed in the range of 0 to 100 nm. Even in any of the examples, the formation of the surface treatment layer was carried out under the following conditions.

The hydrogen concentration and the carbon concentration in the surface treatment layer 20 (tantalum layer) were measured. This measurement was carried out by using Pelletron 3SDH (manufactured by National Electrostatics Corporation) by Raspford backscattering spectrometry (RBS), hydrogen forward scattering analysis (HFS) or nuclear reaction analysis (NRA). Further, the content of the ruthenium element in the surface treatment layer 20 (ruthenium layer) was measured using a high-frequency glow discharge light-emitting surface analyzer (GDS). These results are as shown in Tables 1 and 2.

(1f) Formation of primer resin layer

As the evaluation sample, a sample in which a primer resin layer was formed on the surface treatment layer, and a sample in which a primer resin layer was not formed on the surface treatment layer were used. The preparation of the sample in which the primer resin layer was formed was carried out as follows. First, a mixed varnish of o-cresol novolak type epoxy resin (manufactured by Tohto Kasei Co., Ltd., YDCN-704), a solvent-soluble aromatic polyamide resin polymer and a solvent (Japanese Chemical Co., Ltd. limited) is prepared. The company manufactures, BPAM-155) as a raw material. In the mixed varnish, a phenol resin (manufactured by Dainippon Ink Co., Ltd., VH-4170) and a hardening accelerator (manufactured by Shikoku Chemical Industry Co., Ltd., 2E4MZ) were added as a curing agent. A resin composition having the blending ratio shown below is obtained.

<Material ratio of resin composition>

O-cresol novolac type epoxy resin: 38 parts by weight

Aromatic polyamide resin polymer: 50 parts by weight

Phenolic resin: 18 parts by weight

Hardening accelerator: 0.1 parts by weight

A resin solution was prepared so that methyl ethyl ketone was added to the resin composition and the solid content of the resin was 30% by weight. As shown in Fig. 1, the obtained resin solution 21 was applied onto the surface treatment layer 20 (ruthenium layer) of the copper foil 10 having a carrier using a gravure coater. Further, air drying was carried out for 5 minutes, and then dried in an atmosphere of 140 ° C for 3 minutes, and a primer resin layer 22 having a thickness of 1.5 μm in a semi-hardened state was formed.

(2) Production of copper-clad laminate

As shown in Fig. 2, the copper-clad laminate 28 was produced as follows using the copper foil 24 having the carrier and the resin substrate 26.

(2a) Production of resin substrate

Four sheets of a prepreg (manufactured by Mitsubishi Gas Chemical Co., Ltd., GHPL-830NS, thickness: 45 μm) made of a glass fiber-containing bismaleimide-triazabenzene resin were placed in a laminate to prepare a resin substrate 26.

(2b) laminate

The copper foil 24 having a carrier sandwiches both sides of the resin substrate 26 (in FIG. 2, for simplicity, only one side of the laminate), at a stamping temperature of 220 ° C, a stamping time: 90 minutes, and a pressure of 40 MPa. A laminated resin substrate 26 and a copper foil 24 having a carrier are laminated. In this way, the copper-clad laminate 25 having the carrier is obtained.

(2c) stripping of the carrier

The surface of the ultra-thin copper foil layer 18 is exposed by peeling off the carrier 12 from the peeling layer 16 of the copper-clad laminate 25 having a carrier. Further, the heat resistant metal layer 14 and the peeling layer 16 are peeled off while being attached to the side of the carrier 12 (electrolytic copper foil). In this way, the copper-clad laminate 28 is obtained.

(3) Evaluation

With respect to the thus obtained copper-clad laminate, (3a) evaluation of peel strength, (3c) evaluation of fine wiring pattern formation, and (3d) interface observation by STEM-EDS and element mapping measurement were performed. Further, the surface treatment layer (3b) which is equivalent to the surface treatment layer of the copper-clad laminate is also prepared for evaluation of the insulation resistance of the surface treatment layer. Specifically, it is as follows.

(3a) Evaluation of peel strength

As shown in Fig. 3, a sample 32 for peel strength measurement was prepared from the copper-clad laminate 28, and the surface treatment layer 20 of the ultra-thin copper foil 18 and the primer tree were evaluated. Peel strength of the lipid layer 22. The peeling strength measurement sample 32 was produced by forming a copper-plated copper 30 having a thickness of 18 μm on a copper-clad laminate 28 using a sulfuric acid copper plating solution, followed by patterning. Further, the pattern formation was performed by masking the formed copper plating with a width of 10 mm and etching it with an aqueous solution of copper dichloride.

The measurement of the peel strength was carried out by measuring the three points under the conditions that the peel strength of the sample was set to an angle of 90° and a speed of 50 mm/min, and the average value thereof was used. Further, the peel strength (average value) thus obtained was evaluated in the three stages of A, B, and C in accordance with the following criteria. The results are as shown in Tables 1 and 2.

<Evaluation Benchmark>

A: 400gf/cm or more

B: 300gf/cm or more and 400gf/cm is not full

C: 300gf/cm is not full

(3b) Evaluation of the insulation resistance of the surface treatment layer

The samples for insulation resistance measurement corresponding to the surface treatment layers of Examples 1 to 15 were produced, and the insulation resistance was evaluated. The sample for measuring the insulation resistance was formed on the glass substrate (manufactured by Corning Incorporated, #1737) under the same conditions as those described in the above-mentioned "(1e) surface treatment layer formation", and a surface treatment layer having a thickness of 100 nm was formed. (矽 layer) to carry out. For the measurement sample thus obtained, a semiconductor device analyzer (manufactured by Agilent Technologies, Inc., B1500A) was used to measure the four-terminal method. The obtained specific resistance value ρ (Ω.cm) was converted into a film thickness of 6 nm, and the sheet resistance value (Ω·□) of (ρ×100/6) was used as an evaluation index of the insulation resistance. Further, the sheet resistance values thus obtained were evaluated in the three stages of A, B, and C in accordance with the following criteria. The results are as shown in Tables 1 and 2.

<Evaluation Benchmark>

A: 1.0 × 10 ¹² Ω / □ or more

B: 1.0 × 10 ¹⁰ Ω / □ or more 1 × 10 ¹² Ω / □ is not full

C: 1.0 × 10 ¹⁰ Ω / □ is not full

(3c) Evaluation of fine wiring pattern formation

As shown in FIG. 4, the copper-clad laminate 28 obtained in each example was formed into a fine wiring pattern 38, and the pattern processability was evaluated. First, a sample for evaluation of a fine wiring pattern was produced as follows.

(i) photoresist coating

A positive photoresist (TMMRP-W1000T, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to the ultra-thin copper foil layer 18 of the copper-clad laminate 28.

(ii) Exposure processing

The copper-clad laminate 28 coated with the photoresist was subjected to exposure treatment under the following conditions.

Pattern: Line/Space=2/2μm, pattern length 2mm

Glass mask: chrome evaporation mask

Exposure: 180mJ/cm ² (wavelength: converted to 365nm, mercury spectral line)

(iii) Imaging

The copper-clad laminate 28 subjected to the exposure treatment was subjected to development processing under the following conditions, and the pattern of the photoresist 34 was formed as shown in Fig. 4(a).

Imaging solution: TMAH aqueous solution (manufactured by Tokyo Yinghua Industrial Co., Ltd., NMD-3)

Temperature: 23 ° C

Treatment method: immersion for 1 minute × 2 times

(iv) Electroplated copper

On the extremely thin copper foil layer 18 of the copper-clad laminate 28 which was patterned by the development processing, as shown in Fig. 4 (b), the electroplated copper 36 having a thickness of 2 μm was formed by a sulfuric acid copper plating solution.

(v) Stripping of photoresist

The copper-clad laminate 28 to which the electroplated copper 36 is applied is peeled off by the photoresist 34 under the following conditions, and is in a state shown in Fig. 4(c).

Stripping solution: ST106 aqueous solution (manufactured by Tokyo Yinghua Industrial Co., Ltd.)

Temperature: 60 ° C

Time: 5 minutes

(vi) Copper etching (flash erosion)

The copper-clad laminate 28 of the peeling resist 34 is subjected to copper etching under the following conditions, and as shown in FIG. 4(d), a fine wiring pattern 38 is formed.

Etching solution: sulfuric acid hydrogen peroxide-based etching solution (manufactured by MEC, QE7300)

Treatment method: impregnation

Temperature: 30 ° C

Time: 30 seconds

(vii) Microscopic observation

The appearance of the obtained fine wiring pattern was observed with an optical microscope (1,750 times), and the occurrence rate of peeling of the wiring was confirmed. The rate of adverse events was assessed according to the following evaluation criteria.

<Evaluation Benchmark>

A: The rate of failure is less than 5% (best)

B: The rate of bad production is 6~10% (good)

C: The rate of failure is 11~20% (allowable)

D: The rate of failure is 21% or more (bad)

The evaluation results obtained are shown in Tables 1 and 2. In addition, FIG. 5 shows an SEM photograph of the fine wiring pattern observed in Example 5 (Example).

(3d) Interface observation and element mapping measurement by STEM-EDS

In the copper-clad laminate 25 having a carrier coated with the primer resin layer 22 prepared in Example 5 (Example), the carrier 12, the ultra-thin copper foil layer 18, and the surface treatment layer 20 were observed by STEM-EDS. When the interface of the primer resin layer 22 is formed, the image shown in Fig. 6A is obtained. The portrait located on the upper side of Fig. 6A is an enlarged portrait of the interface portion surrounded by the circle in the photo on the lower side. Fig. 6B shows a Si element map image of the interface portion indicated by the enlarged image, and Fig. 6C shows a Cu element map image of the interface portion. It is apparent from the comparison of these images that the lanthanum-based surface treatment layer 20 is formed on the surface of the ultra-thin copper foil layer 18.

10‧‧‧ Copper foil with carrier

12‧‧‧ Carrier

14‧‧‧heat resistant metal layer

16‧‧‧ peeling layer

18‧‧‧very thin copper foil layer

20‧‧‧Surface treatment layer

21‧‧‧Resin solution

22‧‧‧ Primer resin layer

24‧‧‧With copper foil with carrier

Claims (13)

A surface-treated copper foil comprising: a copper foil; and a surface treatment layer made of tantalum provided on at least one side of the copper foil and having a hydrogen concentration of 1 to 35 atom% and a carbon concentration of 1 to 15 atom%. The surface-treated copper foil according to claim 1, wherein the surface-treated copper foil is used for the production of a copper-clad laminate for a printed wiring board, and in the production, a resin layer is laminated on the surface treatment layer. The surface-treated copper foil according to claim 1, wherein the surface treatment layer has a thickness of 0.1 to 100 nm. The surface-treated copper foil according to claim 1, wherein the surface of the copper foil on the surface-treated layer side has an arithmetic mean roughness Ra of 100 nm or less measured according to JIS B 0601-2001. The surface-treated copper foil according to claim 1, wherein the surface treatment layer has a hydrogen concentration of 10 to 30 atom%. The surface-treated copper foil according to claim 1, wherein the surface treatment layer has a carbon concentration of 3 to 13 atom%. The surface-treated copper foil according to claim 1, wherein the copper foil has a thickness of 50 to 1000 nm. A copper-clad laminate for a printed wiring board, comprising the surface-treated copper foil according to any one of claims 1 to 7, and a resin layer provided in close contact with the surface-treated layer. A printed wiring board comprising: sequentially laminating a resin layer, having a hydrogen concentration of 1 to 35 atom% and a carbon concentration of 1 ~15 atomic % consists of a layer composed of tantalum and a layer of a copper layer. A method of producing a surface-treated copper foil according to any one of claims 1 to 7, comprising: preparing a copper foil; and forming a film or chemical by physical vapor phase The vapor phase film formation is performed on at least one side of the copper foil to form a surface treatment layer composed of ruthenium having a hydrogen concentration of 1 to 35 atom% and a carbon concentration of 1 to 15 atom%. The method for producing a surface-treated copper foil according to claim 10, wherein the surface treatment layer is formed by physical vapor deposition, and the physical vapor deposition is performed by sputtering. The method for producing a surface-treated copper foil according to claim 10, wherein the physical vapor phase film formation uses a ruthenium target and/or a ruthenium carbide target, and in a non-oxidizing atmosphere, a carbon source and a hydrogen source are contained. At least one additional component is carried out simultaneously. The method for producing a surface-treated copper foil according to claim 12, wherein the additive component is at least one selected from the group consisting of methane, ethane, propane, butane, acetylene and tetraethoxydecane. As raw material.